Gmail Themes. That's Totally Ninja.
J. Michael Arrington (born March 13, 1970 in Huntington Beach, California) is a serial entrepreneur and the founder of TechCrunch, a blog covering startups and technology news.
Arrington attended Claremont McKenna College (BA Economics, 1992) and Stanford Law School (JD, 1995), and practiced as a corporate and securities lawyer at two law firms: O’Melveny & Myers and Wilson Sonsini Goodrich... → Learn More

Apparently a lucky few Gmail users had a “Themes” tab pop up under settings. No longer do you have to suffer through the boring-if-functional standard Gmail interface for the 16 hours a day that you keep the page loaded. Try “Ninja” instead.
Thanks for the tip Dan.